I know it's a bit of a delayed response, but...
You mention the LS50's and their midrange and imaging. I can tell you, in the same room and system with the proper stands with the correct height and angle for the Venere 1.5's, they produced just as good imaging as the LS50's and even better midrange with extended, refined top end. The LS50's on the other hand were just a bit too forward, leaner in the mids, and a little too sparkly on the top end, possibly even a bit sterile or analytical.
And that's all with the same Parasound Halo P5 preamp as you.
Again, you didn't give those Venere 1.5's a chance to show you what they are capable of. Giving them that proper angled tilt back is what gets the drivers and the rest of the crossover design aligned. Without that, they fall short quite easily. That angle is very important with these speakers and is absolutely necessary.